package com.jhws.common;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.jhws.util.LogHelper;


public class SetCharacterEncodingFilter implements Filter {

	protected String encoding;

	protected FilterConfig filterConfig;

	protected boolean ignore;

	public SetCharacterEncodingFilter() {
		encoding = null;
		filterConfig = null;
		ignore = true;
	}

	public void destroy() {
		encoding = null;
		filterConfig = null;
	}

	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {

		if (ignore || request.getCharacterEncoding() == null) {
			String encoding = selectEncoding(request);
			if (encoding != null)
				request.setCharacterEncoding(encoding);
		}

		/* 设置静态资源html永不缓存 */
		HttpServletRequest httpRequest = (HttpServletRequest) request;
		HttpServletResponse httpResponse = (HttpServletResponse) response;
		String uri = httpRequest.getRequestURI();
		if (uri.endsWith(".html")){
			{
				httpResponse.setHeader("Cache-Control","no-cache");
				httpResponse.setHeader("Pragma","no-cache");
				httpResponse.setDateHeader("Expires",0);
			}
		}


        chain.doFilter(request, response);


	}

	public void init(FilterConfig filterConfig) throws ServletException {
		this.filterConfig = filterConfig;
		encoding = filterConfig.getInitParameter("encoding");
		String value = filterConfig.getInitParameter("ignore");
		if (value == null)
			ignore = true;
		else if (value.equalsIgnoreCase("true"))
			ignore = true;
		else if (value.equalsIgnoreCase("yes"))
			ignore = true;
		else
			ignore = false;
	}

	protected String selectEncoding(ServletRequest request) {
		return encoding;
	}


}
